47 Fun Facts About Tyrannosaurus Rex

What does the 'rex' in Tyrannosaurus rex mean?

King. The full name means 'tyrant lizard king', and it only just stuck: scrappy bones named Manospondylus gigas, 'giant porous vertebra', back in 1892 turned out to belong to the same animal.

On which island continent, now part of western North America, did Tyrannosaurus live?

Laramidia. A shallow inland sea cut North America in two for millions of years, and T. rex roamed the western half, a long strip of land running from what is now Alaska down to Mexico.

Despite starring in Jurassic Park, T. rex lived at the very end of which geological period?

Cretaceous. T. rex turned up only in the period's last couple of million years, so less time separates it from us than separated it from the Jurassic's Stegosaurus.

How many clawed fingers did Tyrannosaurus have on each hand?

Two. Each tiny arm ended in two clawed fingers, yet the arms were strongly muscled, and some scientists think they helped a fallen T. rex push itself back onto its feet.

Which meat-eating dinosaur is thought to have been even longer than T. rex?

Spinosaurus. The sail-backed giant from North Africa stretched to about 14 metres, a little longer than any T. rex, but it mostly ate fish and had died out more than 20 million years earlier.

Which Asian dinosaur is so close to Tyrannosaurus that some treat it as a species of the same genus?

Tarbosaurus bataar. The Mongolian giant was first named Tyrannosaurus bataar, and a smuggled skeleton that fetched over $1 million at a New York auction in 2012 was seized and sent home to Mongolia.

Who found the first partial T. rex skeleton, in eastern Wyoming in 1900?

Barnum Brown. The American Museum's fossil hunter struck again in Montana in 1902, and it was that second skeleton, not his first, that the species was named from.

Who named Tyrannosaurus rex in 1905?

Henry Fairfield Osborn. In the same 1905 paper he called another skeleton Dynamosaurus imperiosus, then realised both were one species; T. rex survived because it came first in print.

Which web browser lets you play as a pixelated T. rex when your internet connection drops?

Chrome. Google's designers chose a dinosaur as a joke about being sent back to the prehistoric age without Wi-Fi, and codenamed the game Project Bolan after the singer of the band T. Rex.

Why did New York's American Museum sell its original T. rex skeleton in 1941?

Bombing fears. With the Second World War under way the museum feared air raids on New York, so the skeleton the species is named from went to Pittsburgh's Carnegie Museum and never came back.

Sue, the most complete T. rex yet found, takes its name from whom?

Its discoverer. Sue Hendrickson spotted a few big bones jutting from a South Dakota cliff in 1990; despite the name, nobody knows whether the dinosaur itself was male or female.

Which fast-food chain helped buy Sue the T. rex in 1997?

McDonald's. It teamed up with Disney to back the winning bid of around $8 million, then paid for a lab behind glass where the public could watch the bones being cleaned.

Sue the T. rex is on permanent display in which city?

Chicago. Sue greeted visitors in the Field Museum's main hall for 18 years, then moved in 2018 to a private gallery where the skeleton gained the belly ribs left off the first mount.

Which part of Sue the T. rex sits in its own display case instead of on the skeleton?

The skull. The real one weighs about 600 pounds and scientists want it within reach, so the skeleton wears a lighter cast while the original sits in a case that opens for study.

Stan, the T. rex sold for $31.8 million in 2020, was auctioned by which house?

Christie's. The anonymous buyer kept Stan out of sight for about a year and a half, worrying scientists, before the skeleton resurfaced as the star of a new natural history museum in Abu Dhabi.

Jurassic Park wrongly claims a T. rex cannot see you if you do what?

Stand perfectly still. Palaeontologists call the film's tip complete fiction: the real animal had keen, forward-facing eyes, so freezing in front of one would only have made its dinner easier.

Bucky, found by 20-year-old Bucky Derflinger in 1998, was the first T. rex to preserve which bone?

The furcula, or wishbone. Wishbones are a trademark of living birds, so finding one inside a teenage T. rex was one more sign that birds and dinosaurs are kin.

Scotty, perhaps the heaviest T. rex known, comes not from Alberta but from which other Canadian province?

Saskatchewan. The skeleton is named after the bottle of Scotch its finders shared to celebrate in 1991, and freeing the bones from iron-hard sandstone then took more than a decade.

Trix, a T. rex named after a former queen, is the star of a museum in which country?

Netherlands. Leiden's Naturalis museum dug her up in Montana, the Dutch public chipped in ten euros at a time to bring her home, and she was named after the former Queen Beatrix.

The asteroid that wiped out T. rex 66 million years ago struck what is now which country?

Mexico. The asteroid, some 10 km across, left a vast crater now buried beneath the Yucatan coast, and its age matches the last dinosaur fossils exactly.

T. rex's huge teeth have been memorably likened to which fruit?

Bananas. One palaeontologist called them 'lethal bananas': thick, curved and ridged, they were built to punch into bone and hold on, not to slice like the dagger teeth of other predators.

Which film star sparked rumours of buying Stan by showing a T. rex skull during a 2022 NFL broadcast?

Dwayne Johnson. The Rock's trophy was a replica: the firm that dug Stan up had sold him a cast of the skull, and the real skeleton's secret buyer turned out to be a museum.

Which job have scientists seriously proposed for T. rex's tiny arms?

Gripping a mate. That 1906 suggestion is the oldest of many; others argue the metre-long arms slashed at prey with their claws, and the question is still open.

Which palaeontologist championed the idea that T. rex was purely a scavenger, not a predator?

Jack Horner. The palaeontologist said to have inspired Jurassic Park's hero preached his scavenger theory for years to a largely unconvinced field, pointing to T. rex's puny arms and keen nose.

Healed marks read as T. rex bites on the skull of which dinosaur suggest it survived a clash?

Triceratops. The marks sit on a brow horn and the neck frill, and the horn had snapped and then begun to heal, so if a T. rex made them, this one walked away from the meeting.

Tooth marks on the foot bones and humerus of several T. rex specimens are evidence of what behaviour?

Cannibalism. The marks look like feeding rather than fighting, so a T. rex probably scavenged the carcass of one of its own kind when it got the chance.

Holes in the jaw of Sue the T. rex, once read as bites, were blamed in 2009 on what?

Parasites. A 2009 study matched the holes to an infection that still eats into the jaws of modern raptors, and argued that a bad case could have left Sue unable to feed and starving.

A 2017 computer model found an adult T. rex would have broken its leg bones if it tried to do what?

Run. The model found a true running gait would have overloaded the skeleton, limiting adults to a brisk walk of about 12 mph, so the jeep in Jurassic Park would have got away easily.

One study found that T. rex beat a hawk at which visual skill?

Judging distance. Its eyes faced forward enough to overlap across 55 degrees, a wider field than a hawk's, and its snout grew lower and narrower over time to clear the view.

T. rex's sense of smell has been compared to that of which modern bird?

Vultures. The smell-processing bulbs of its brain were unusually large, so T. rex could probably track a carcass, or living prey, from a long way off.

In 2005 Mary Higby Schweitzer announced the recovery of what from a T. rex fossil?

Soft tissue. Dissolving the mineral from a broken thigh bone left stretchy, see-through blood vessels, a find so unexpected that sceptics argued it had to be bacterial slime.

Which large feathered T. rex relative cast doubt on big tyrannosaurs having lost their feathers?

Yutyrannus. The Chinese giant wore long, shaggy filaments, but it lived somewhere cold; skin impressions from T. rex itself show scales, so any feathers it kept were probably few.

A 2022 study of chemical traces in fossil bone concluded that T. rex was what?

Warm-blooded. By-products of metabolism locked in the bone pointed to an engine running as hot as a modern bird's, not a giant kept warm by its bulk alone.

Jane, long argued to be a teenage T. rex, was named in 2025 as a species of which genus?

Nanotyrannus. For two decades Jane was at the centre of a row over whether the 'dwarf tyrant' was only a young T. rex, until a 2025 study of a nearly full-grown skeleton ruled it a separate animal.

Which fossil formation, spanning Montana and the Dakotas, has produced Sue, Stan, Bucky and Jane?

Hell Creek. Its rocks were laid down in the last stretch before the asteroid struck, the only window in which T. rex existed, which makes its badlands the richest hunting ground for them anywhere.

A 1998 study described a coprolite attributed to T. rex, which is what kind of fossil?

Fossilised droppings. The crushed bone inside, from a plant-eating dinosaur, shows that T. rex swallowed what it crunched instead of picking round the skeleton.

Why do loose T. rex teeth turn up so often as fossils?

It regrew teeth all its life. A T. rex kept shedding worn teeth and growing replacements, so every animal left a trail of them, and they are far easier to find than skeletons.

Philip Currie argued from tyrannosaur skeletons found buried together that T. rex may have done what?

Hunted in packs. Sceptics say animals found together may only have died together in a flood or drought, though parallel tracks of three tyrannosaurs in Canada keep the idea alive.

Which agency raided a South Dakota fossil lab in 1992 and seized Sue the T. rex?

The FBI. Agents hauled the bones away in a row over who owned them; a court handed Sue back to the landowner who had taken $5,000 for her, and he sold her at auction for millions.

Which children's TV character is, officially, a Tyrannosaurus rex?

Barney. The plush purple star of Barney & Friends is a T. rex with the menace taken out; a Texas mother invented him in 1988 after finding nothing on television worth showing her two-year-old.

In Jurassic Park, the T. rex escapes because what has been switched off?

The electric fences. A bribed programmer shuts down the park's security so he can smuggle out dinosaur embryos, and the power to the paddocks goes with it just as a storm hits.

Which character does the T. rex devour in Jurassic Park?

Gennaro. The lawyer is snatched off a toilet after abandoning the children, a death the film borrowed from another character: in Michael Crichton's novel Gennaro survives the island.

The palaeontologist who found the first T. rex skeletons was known by what nickname?

Mr Bones. He earned it through an uncanny knack for finding fossils and getting them out of the ground unbroken, a talent that kept New York's American Museum in dinosaurs for six decades.

The T. rex roar in Jurassic Park was built around the slowed-down cry of a baby what?

Elephant. Sound designer Gary Rydstrom says a small animal's cry, slowed down, proved more interesting than a big one's roar; the calf made the squeal only once, so every T. rex roar in the film reuses that one recording.

A 2021 study estimated the adult Tyrannosaurus population alive at any one time at roughly how many?

20,000. Over the species' whole run that still adds up to about 2.5 billion animals, yet the same study reckoned that only about one in 80 million left a fossil we have found.

Collagen proteins recovered from T. rex bone in 2007 most closely matched those of which living animal?

Chicken. Scraps of protein teased from a 68-million-year-old thigh bone lined up best with a hen's, chemical backing for birds as living dinosaurs, though critics doubt the samples were clean.

The unusually long hearing organ in T. rex's inner ear suggests it heard best in which range of sound?

Low frequency. Deep rumbles carry a long way, so T. rex could probably pick up the movements of distant prey, and it may well have made low sounds of its own.